1. Field of Technology
The present invention relates to a data processing apparatus having an intermediate roller forming the inside surface of a curved transportation unit that is curved in an arc shape, a guide forming the outside surface of this curved transportation unit, and a pair of paper transportation rollers, which nip and convey a transported medium delivered from the curved transportation unit to a processing position, disposed at a position separated a specific distance from the output end of the curved transportation unit.
2. Description of Related Art
A printer connected to a personal computer, for example, is described below as an example of a data processing apparatus according to the present invention.
Disposed inside the housing that provides the external appearance of a printer are a transportation mechanism for conveying paper as the transported medium from a paper tray, cassette, or other storage unit one sheet at a time along a specific transportation path, a recording unit disposed at some intermediate position along the transportation path for recording text, graphics, or other images to the conveyed paper, and various operating devices such as a recording unit drive mechanism for imparting a specific motion to the recording unit as needed for printing.
In order to reduce the footprint and reduce the size of the printer, some printers have both the paper feed unit and the discharge unit for discharging the printed paper disposed to feed and discharge the paper from openings at the front of the printer. This type of printer typically has a paper cassette used to store paper for supplying to the print unit disposed at the bottom front part of the printer housing, and a discharge tray onto which the printer paper is deposited after printing disposed above the paper cassette. A substantially U-shaped transportation path connecting the paper cassette to the discharge tray is rendered inside the housing, and the recording unit is disposed to this U-shaped transportation path.
The U-shaped transportation path inside the housing is composed of a curved transportation unit, a paper feed roller pair, and a discharge transportation mechanism. The curved transportation unit starts from the paper cassette storing the paper, and has an intermediate roller unit and a guide portion that curves around the roller unit. The paper feed roller pair is located a specific distance from the output end of the curved transportation unit. The discharge transportation mechanism guides the paper past the recording unit, which is located downstream from the paper feed roller pair, to the discharge tray at the front of the printer.
A problem with this arrangement is that paper jams occur easily inside the curved transportation unit and in the area from the curved transportation unit to the paper feed roller pair due to skewing and curling in the leading end of the paper. To avoid this problem, Japanese Unexamined Patent Appl. Pub. 2003-154693 teaches a contact release mechanism for separating the rollers of the transportation unit from the paper when a paper jam occurs.
The contact release mechanism taught in Japanese Unexamined Patent Appl. Pub. 2003-154693 releases the roller pressure on the paper when the jammed end of the paper is held to extract the paper from the paper supply or paper discharge side, so that the paper can be easily removed.
In addition, Japanese Patent 2529261 teaches an arrangement for exposing the curved transportation unit for access from the outside by pivoting the guide portion of the curved transportation unit open and closed in conjunction with the external cover of the housing in order to facilitate removing jammed paper that is stuck inside the printer due to a paper jam in the U-shaped transportation path.
In order to prevent paper jams in the U-shaped transportation path described above, the curling and skewing at the leading end of the paper that cause paper jams must be prevented between the curved transportation unit and the paper feed roller pair. However, if the guide portion of the curved transportation unit that guides the paper between the curved transportation unit and the paper feed roller pair is extended to the paper feed roller pair, opening the guide portion of the curved transportation unit when a paper jam occurs interferes with other members inside the housing and it is thus difficult to expose the curved transportation unit for access from outside the housing.
A data processing apparatus according to at least one embodiment of the present invention having a structure for guiding paper (transported medium) from a curved transportation unit to a paper feed roller pair makes it possible to externally expose the curved transportation unit by opening a closable guide portion, thus affording highly stable transportation through the U-shaped transportation path and easy removal of a transported medium jammed inside the transportation path.